Instantaneous start of USART transmission wanted

[jhochreiter]

Posted on May 17, 2013 at 07:50

Hi everyone,

I have an application where I have to start transmission of a single byte from a USART within a small time frame after a hardware signal. Unfortunely a simple start by writing to the USARTs DR-register starts transmission with a 'random' delay of up to 1 bit time (probably due to the current content of the prescaler). Is there a way to get rid of that start-of-transmission-jitter ? Best regards, Johann #usart-transmission-jitter

[Tesla DeLorean]

Posted on May 17, 2013 at 13:13

External signals are resynchronized, divider chains are not reset, responsiveness of the USART will be synchronous with the baud clock. Want to reduce that, increase the baud rate.

You could try changing BRR, or parking it at a low value before setting what you want.